1. Field of the Invention
The present invention relates to a power split device and method.
2. Related Art
In multiple-power source devices, such as, for example, hybrid vehicles, arrangements exist to distribute power between elements of the vehicle. For example, it is known in a so-called “parallel” hybrid vehicle to provide a planetary gear power train which links an internal combustion engine, the driven road wheels and any electric machines. The planetary gear hybrid power train provides two power paths between the internal combustion engine and the driven road wheels. The first power path may be a mechanical coupling between the internal combustion engine and the driven wheels, whilst the second power path may be via a motor-generator and battery arrangement.
This approach enables the two power paths to be utilized under different conditions to improve the overall efficiency of the vehicle. However, whilst the planetary gear power train is simple and fairly efficient it suffers from a number of limitations. Accordingly, it is desired to provide an improved power split device.